diff -up firefox-124.0/toolkit/xre/nsAppRunner.cpp.fedora-customization firefox-124.0/toolkit/xre/nsAppRunner.cpp
diff -up firefox-124.0/widget/gtk/nsWindow.cpp.fedora-customization firefox-124.0/widget/gtk/nsWindow.cpp
--- firefox-124.0/widget/gtk/nsWindow.cpp.fedora-customization	2024-03-13 12:35:57.098591719 +0100
+++ firefox-124.0/widget/gtk/nsWindow.cpp	2024-03-13 12:43:17.375928494 +0100
@@ -3459,6 +3459,12 @@ nsresult nsWindow::SetTitle(const nsAStr
     return NS_OK;
   }
 
+  const char* appTitle = getenv("MOZ_APP_TITLE");
+  if (appTitle) {
+    gtk_window_set_title(GTK_WINDOW(mShell), appTitle);
+    return NS_OK;
+  }
+
   // convert the string into utf8 and set the title.
 #define UTF8_FOLLOWBYTE(ch) (((ch) & 0xC0) == 0x80)
   NS_ConvertUTF16toUTF8 titleUTF8(aTitle);